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81.
82.
Rimjhim Bhatnagar Singh S. S. Ray S. K. Bal B. S. Sekhon G. S. Gill Sushma Panigrahy 《Journal of the Indian Society of Remote Sensing》2013,41(2):301-308
Crop residue has become an increasingly important factor in agriculture management. It assists in the reduction of soil erosion and is an important source of soil organic carbon (soil carbon sequestration). In recent past, remote sensing, especially narrowband, data have been explored for crop residue assessment. In this context, a study was carried out to identify different narrow-bands and evaluate the performance of SWIR region based spectral indices for crop residue discrimination. Ground based hyperspectral data collected for wheat crop residue was analyzed using Stepwise Discriminant Analysis (SDA) technique to select significant bands for discrimination. Out of the seven best bands selected to discriminate between matured crop, straw heap, combine-harvested field with stubbles and soil, four bands were from SWIR (1980, 2030, 2200, 2440 nm) region. Six spectral indices were computed, namely CAI, LCA, SINDRI, NDSVI, NDI5 and hSINDRI for crop residue discrimination. LCA and CAI showed to be best (F?>?115) in discriminating above classes, while LCA and SINDRI were best (F?>?100) among all indices in discriminating crop residue under different harvesting methods. Comparison of different spectral resolution (from 1 nm to 150 nm) showed that for crop residue discrimination a resolution of 100 nm at 2100–2300 m region would be sufficient to discriminate crop residue from other co-existing classes. 相似文献
83.
Huiye Ma Nicole Ronald Theo A. Arentze Harry J. P. Timmermans 《Journal of Geographical Systems》2013,15(4):427-451
Agent-based simulation has become an important modeling approach in activity-travel analysis. Social activities account for a large amount of travel and have an important effect on activity-travel scheduling. Participants in joint activities usually have various options regarding location, participants, and timing and take different approaches to make their decisions. In this context, joint activity participation requires negotiation among agents involved, so that conflicts among the agents can be addressed. Existing mechanisms do not fully provide a solution when utility functions of agents are nonlinear and non-monotonic. Considering activity-travel scheduling in time and space as an application, we propose a novel negotiation approach, which takes into account these properties, such as continuous and discrete issues, and nonlinear and non-monotonic utility functions, by defining a concession strategy and a search mechanism. The results of experiments show that agents having these properties can negotiate efficiently. Furthermore, the negotiation procedure affects individuals’ choices of location, timing, duration, and participants. 相似文献
84.
P. Jayaprasad B. Narender S. K. Pathan Ajai 《Journal of the Indian Society of Remote Sensing》2008,36(4):313-322
Digital elevation model (DEM) and the derived terrain parameters e.g. contour, slope, aspect, drainage pattern, etc are required
for natural resources management, infrastructure planning and disaster management. The present paper aims at generating DEM
from ERS tandem pair using interferometric technique supported by differential GPS measurements (DGPS) and multispectral optical
data. Validation of DEM has been carried out by DGPS measurements. Ground Control Points (GCP) established by DGPS measurements
have been used to georeference the IRS-1D optical data that has finally been co-registered with SAR amplitude image. Optical
data, co-registered with ERS - I SAR data has helped in locating the GCP’s and check points, precisely, for refinement of
DEM and its validation. 相似文献
85.
An evaluation of some systematic error sources affecting terrestrial gravity anomalies 总被引:1,自引:2,他引:1
B. Heck 《Journal of Geodesy》1990,64(1):88-108
Terrestrial free-air gravity anomalies form a most essential data source in the framework of gravity field determination.
Gravity anomalies depend on the datums of the gravity, vertical, and horizontal networks as well as on the definition of a
normal gravity field; thus gravity anomaly data are affected in a systematic way by inconsistencies of the local datums with
respect to a global datum, by the use of a simplified free-air reduction procedure and of different kinds of height system.
These systematic errors in free-air gravity anomaly data cause systematic effects in gravity field related quantities like
e.g. absolute and relative geoidal heights or height anomalies calculated from gravity anomaly data.
In detail it is shown that the effects of horizontal datum inconsistencies have been underestimated in the past. The corresponding
systematic errors in gravity anomalies are maximum in mid-latitudes and can be as large as the errors induced by gravity and
vertical datum and height system inconsistencies. As an example the situation in Australia is evaluated in more detail: The
deviations between the national Australian horizontal datum and a global datum produce a systematic error in the free-air
gravity anomalies of about −0.10 mgal which value is nearly constant over the continent 相似文献
86.
B. K. Sinha Ashok Kumar Deepak Shrivastava Sanjay Srivastava 《Journal of the Indian Society of Remote Sensing》1990,18(3):1-8
In recent years satellite remote sensing techniques have greatly aided identification of fractures/joints/faults in connection with groundwater exploration. However, due to some constraints in filtering out the type of fracture i.e. shear fracture, tensional fracture, mineralised fracture etc. as to their “open or closed” nature from groundwater aspects, there is need of adding geophysical survey, particularly resistivity survey to further enhance the accuracy, and hence minimise drilling failures. The area under study is a part of Ranchi plateau and lithologically comprising of granite-gneiss. The present paper lays stress on an integrated approach for localising well sites through satellite data analysis and resistivity profiling along with vertical electrical sounding which is based on fracture patterns. With this combined effort i.e. firstly considering the surfacial features like drainage, geomorpho-logy, lithology and lineaments, and secondly taking into account geophysical survey aspects, i.e. depth and thickness of fracture zone, lateral extent, different layer parameter, etc., fairly accurate results are achieved. In the presnt study this type of an integrated survey has been carried out in Lohardaga and Gumla districts in Bihar, the results of which are highlighted in the paper. 相似文献
87.
Dhruvesh P Patel Mrugen B Dholakia N. Naresh Prashant K. Srivastava 《Journal of the Indian Society of Remote Sensing》2012,40(2):299-312
Geo-visualization concept has been used for positioning water harvesting structures in Varekhadi watershed consisting of 26
mini watersheds, falling in Lower Tapi Basin (LTB), Surat district, Gujarat state. For prioritization of the mini watersheds,
morphometric analysis was utilized by using the linear parameters such as bifurcation ratio (Rb), drainage density (Dd), stream frequency (Fu), texture ratio (T), length of overland flow (Lo) and the shape parameter such as form factor (Rf), shape factor (Bs), elongation ratio (Re), compactness constant (Cc) and circularity ratio (Rc). The different prioritization ranks were assigned after evaluation of the compound factor. 3 Dimensional (3D) Elevation
Model (DEM) from Shuttle Radar Topography Mission (SRTM) and DEM from topo contour were analyzed in ArcScene 9.1 and the fly
tool was utilized for the Geo-visualization of Varekhadi mini watersheds as per the priority ranks. Combining this with soil
map and slope map, the best feasibility of positioning check dams in mini-watershed no. 1, 5 and 24 has been proposed, after
validation of the sites. 相似文献
88.
Mehmet ?ahin B. Yi?it Y?ld?z Ozan ?enkal Vedat Pe?temalc? 《Journal of the Indian Society of Remote Sensing》2012,40(3):399-409
This study introduces artificial neural networks (ANNs) for the estimation of land surface temperature (LST) using meteorological and geographical data in Turkey (26?C45°E and 36?C42°N). A generalized regression neural network (GRNN) was used in the network. In order to train the neural network, meteorological and geographical data for the period from January 2002 to December 2002 for 10 stations (Adana, Afyon, Ankara, Eski?ehir, ?stanbul, ?zmir, Konya, Malatya, Rize, Sivas) spread over Turkey were used as training (six stations) and testing (four stations) data. Latitude, longitude, elevation and mean air temperature are used in the input layer of the network. Land surface temperature is the output. However, land surface temperature has been estimated as monthly mean by using NOAA-AVHRR satellite data in the thermal range over 10 stations in Turkey. The RMSE between the estimated and ground values for monthly mean with ANN temperature(LSTANN) and Becker and Li temperature(LSTB-L) method values have been found as 0.077?K and 0.091?K (training stations), 0.045?K and 0.003?K (testing stations), respectively. 相似文献
89.
90.
Eric J.E. Molin Harmen Oppewal Harry J.P. Timmermans 《Journal of Geographical Systems》2002,4(4):343-358
In this paper, two approaches for measuring residential group preferences, based on the method of Hierarchical Information
Integration (HII), are compared. In particular, the hypothesis that group-based preference models estimated from integrated
HII experiments better predict group preferences than part individual-based group models estimated from classical HII experiments
is tested. To that effect, the models' ability to predict group preferences for new residential alternatives is compared in
a study of residential preferences of co-ops. Results indicate that integrated HII group experiments indeed result in better
predictions of residential preferences. 相似文献